2-(tert-Butoxy­carbonyl­amino)-6-(1,3-dioxo-1H-2,3-dihydro­benzo[de]isoquinolin-2-yl)hexa­noic acid

In the title naphthalimide derivative, C(23)H(26)N(2)O(6), the 1,8-naphthalimide system is essentially planar [maximum deviation = 0.0456 (16) Å]. A characteristic pattern of alternating long and short C—C bond lengths is observed in the 1,8-naphthalimide unit. The mean planes through the methyl carbamate and acetic acid groups form dihedral angles of 42.30 (9) and 61.59 (9)°, respectively, with the 1,8-naphthalimide plane. In the crystal structure, inter­molecular O—H⋯O and C—H⋯O hydrogen bonds link neighbouring mol­ecules, forming R (2) (2)(9) hydrogen-bond ring motifs. These rings are further inter­connected by inter­molecular N—H⋯O and C—H⋯O hydrogen bonds into a three-dimensional supra­molecular network.